Choke means for two-cycle engines



Nov. 4, 1930. H] SP N ER 1,780,635

CHOKE MEANS FOR TWd-CYCLE ENGINES Filed March 21, 1929 Patented Nov. 4, 1930 OWEN H. SPENCER, OF JQTDLANAPOLIS,

CHOKE MEANS roe Applicati n filed March 21, 1512a, s r al orseshoe.

This invention relates to choke mechanisms for internal combustion engines, and isdesigned primarily for use 1n connection -w1th twocycle englnes, and one feature of the invention is the provision of a choke valve between the cylinder feeding mecha- ,nism and the cylinders of the engine for regulating the admission of fuel to the cylinders.

provision of means for operating the choke valve in unison with the valve for the carbureter.

A further feature of the invention. is the 1 provision of means for utilizing the back pressure created by the closing of the choke valve for regulating the speed of the engine, as when idling. Other objects and advantages will be here- 29 inafter more fully set forth and pointed out in the accompanying specification.

In I the accompanying drawing which forms a part of this application, I

The figure is a vertical sectional view thru a two cycle engine with parts broken out. Referring to the drawing the numeral 1 I indicates the cylinder of an-engine, preferably of the two cycle type, 2 indicates the crank case therefor and 3 indicates the piston for the cylinder. said piston being operated in the usual manner from a crank 4, thru the medium of connecting rod 5.

The cylinder 1 has an exhaust port 6 at its lower end and at one side thereof, while 5 a fuel supply port 7 is arranged substan-v tially on the opposite side of the cylinder and substantially in alignment therewith, and communicating with said fuel supply port 7 is a fuel conveying passage 8, the lower end of which communicates with a charger chamber 9. i

Mounted within the chamber 9 is a fuel charger 10 comprising a circular body portion 11 eccentrically and rotatably mounted therein, said body portion having a plurality of radially arranged slots 12, in which are mounted longitudinally movable blades 13, the outer ends of which travel against the peripheral wall of thecharger chamber 9. Communicating with the charger chamber A further feature of. the invention is theclosed, the choke valve w gum the "medium of a portl l, isa c aribureter 15, or the usual or anyprefe'rred structure, thru which fuelis supplied to the charger chamber and thence thru the fuel passage 8 was cylinder l.- 1

Mounted in'the neck 16 of the carbureter '15 isa butterfiy valve 1 7, to which is attached ,an operating lever18. Any suitable means may be attached to the lever-18 and extended to a point in convenient reach of the operator. "In addition to the butterfly valve '17 used for regulating the flow of gaseous fuel "thru the carbureter, a choke valve, 19 is positioned iii-the fuel passage8, said choke valve having a lever 20 for operating-the same,and

in order to operate the choke valve inexact un-ison withgthe butterfly valve 17,a rod 21 is extended from the lever 18to the-lever 20, so that as the butterfly .valve is. opened'or ill be correspondingly opened or closed.

The object of the choke valve 19 is twofold,

to regulate the flow of fuel thru the passage 8, and to create aback pressure a'gainst the chargerllO, which acts as a brake to checkthe r L i momentum ofthe engine-as when running --id-le,-or when'the engine is th'rottled down,

bywhicharrangement the engine is adapted to sensitive speed and power control. d

The choke valve is very essential, owing to the fact that the fuel is entered into the fuel passage 8 with considerable force by the charger structure 10 andby operating it in unison with the butterfly valve 17, said choke valve will be opened and'closed inexact unison with the butterfly valve, and as said choke valve begins to close, a back pressure against the charger 10 will be set up and act as a brakingmedium against the charger and thru the charger to the engine, to reduce the momentum of the engine, the charger 10 being driven directly from the engine.

While the description and drawing illus trate in a general way certain 'instrumentalities which: may be employed in carrying the invention into effect, it is evident that many modificationsmaybe made in the various details without departing from the scope of theappended claims, it being understood that the invention is not restricted to the particular examples herein described.

I claim as my invention:

1. In a choke valve mechanism for an engine, the combination with a cylinder, a fuel passage connecting with said cylinder, a

charging mechanism connecting vwith said fuel passage, a carbureter connecting with said charging mechanism, and a valve associated with said carbureter between said carbureter and charging mechanism, of a choke valve intersecting said fuel passage between said cylinder and charging'mechanism,

whereby the back pressure created by closing said choke valve will not be directed against the carbureter, and means for connecting said choke valve with the valve of the carbureter, whereby when the carbureter valve is moved to open or closed position the choke valve ill will be simultaneously moved to open or closed position. Y

2. In a choke mechanism for an engine, the combination with a cylinder, a fuel passage connecting with said cylinder adjacentthe lower end of the cylinder, a charging mechanism connecting with said passage, a carbureter connecting with said charging mechanism, a butterfly valve associated with said carbureter and between said carbureter and charging mechanism, and a lever for operating said valve, of a choke valve located in said fuel passagebetween said cylinder and charging mechanism, whereby the back pressure created by closing said choke valvewill not be directed against the carbureter, a'lever for operating said choke valve, and a rod connecting the lever of the butterfly valve with the lever 0f the choke valve, whereby said choke valve will be operated when the butterfly valve is operated.

In testimony whereof, I have hereunto set my hand on this the 14th day of March, A. D.

OWEN H. SPENCER. 

